Screen Character Bouncer
Design, code, test and document an assembly language (Intel 80x86) program
that will :
Shift a string of text characters back & forth, a number of times, along a
single row of a text-mode screen.
Each student will have to decide on his/her own values for the following
* the string (3 to 6 characters long);
* the row (any row, except the top 4 rows of the screen);
* the number of back-&-forth cycles (at least 4 cycles);
* the shifting rate (slow enough for the string to be readable on whatever
PC you use to test your program).
The text screen buffer RAM is mapped to segment B800 (for most colour screen
The shifting rate is to be controlled using a software delay, implemented by
a single subroutine. (Do not embed delay code in main routine.)
Include in your submission:
* Executable program file. (On floppy disk, to be returned later.)
* Hardcopy of Program Listing. (eg. printout from Excel or Word or other)
* Hardcopy of Program Description (what it does) and Explanation (its
(for each section and for each operation of your program).
* Partial trace of your main routine. Show how it executes a ‘bounce’ off
the side of the screen.
(Jump over the delay subroutine).
* Partial trace of your delay subroutine (2 or 3 times around each loop).
Include any flags used.
* The Make, Model and Speed (in MHz) of a PC that you tested your program
* A measurement of the time taken to execute your program on the above PC.
* Submit your completed assignment to me, at your scheduled class time, as
Group B: Wed 9th Nov
Group C: Thu 10th Nov
Group A: Mon 14th Nov
* This assignment accounts for 50% of the Laboratory Assessment.